Rachel Jeantel, the last person to speak with Trayvon Martin on the phone before he was shot and killed, told the jury about the confrontation that ended Martin’s life. NBC’s Ron Mott reports.

Crime and courts

This content comes from Closed Captioning that was broadcast along with this program.

>>>we turn to sanford, florida. the trial of george
zimmerman
. the witnesses taking the std, the woman onhe phone with trayvon martin, describing publicly and for the first time what she heard. we get the latest from nbc's ron mott.

>> reporter: today, prosecutors called their most important witness, number eight.

>>he told me the fan started following him.

>> reporter: the 19-year-old was on the phone with her friend, trayvon martin, when he told her a man he described as creepy was following him.

>>you told him to run and he said no.

>>he said no, because he was right by his father's house.

>> reporter: she told of hearing part of the confrontation that ended his life.

>>he said why are you following me for? and then i heard a man saying what are you doing around here?

>> reporter: she then heard this exchange.

>>i heard trayvon say get off, get off.

>>and what did you hear then?

>>seconds later, the phone shut off.

>>oh, my gosh, something horrible is happening.

>> reporter: two residents of the condo complex testified about hearing screams and seeing two people fighting. jane called 911.

>>the last yell for help, who did you believe it to be between the two individuals?

>>the boy. it was like a boy's voice.

>> reporter: but
defense attorneydon west
challenged her.

>>prior to the evening of
february 26
,
2012
, you had never heard trayvon martin's voice.

>>correct. yes.

>>and you had never heard george
zimmerman
's voice.

>>correct.

>> reporter: another witness told the prosecutor who she saw.

>>who was on top?

>>i believe it was
zimmerman
, comparing the size of their bodies.

>> reporter: testimony at odds with
zimmerman
's account. he pleaded not guilty, saying that martin was on top of him, on the attack. mark o'meara questioned whether the neighbor based it on images in the media of a younger martin.

>>you are not certain as you sit here today who was where in that altercation, are you?